1. Technical Field
Various embodiments of the invention relate to methods for brazing aluminum laminate mold tooling, and tooling formed thereby.
2. Background Art
Various tools are conventionally utilized for forming articles using various forming processes, such as injection molding, blow molding, reaction injection molding, die casting, stamping and the like. These tools often include a core block, a cavity block and inserts. The blocks each having opposing forming surfaces for collectively forming an article therebetween. The blocks are often formed separately, and one block translates relative to the other for closing, forming the article, opening, removing the article, and repeating these steps. Often, the blocks are each formed from a solid block of material that is capable of withstanding the stresses, pressures, impacts and other fatigue associated with the forming processes.
These tool components are commonly cooled using cooling channels below the component surface. The cooling efficiency typically determines the quality of the molded component, and how much time it takes to mold the part into a finished solid manufactured part. The cooling efficiency is dependent on the following: thermal properties of the tool material; the geometry of the cooling channels relative to the tool surface; the amount of cooling surface area relative to molded tool or component surface area; thermal properties of molded material; and molding process environment or conditions.
Typical constraints of the molding processes are the thermal properties of molded material, molding process environment or conditions, and, for some applications, thermal properties of the tool or tool component material. With these constraints considered, opportunities to improve the cooling efficiency exist with the geometry of the cooling channels relative to the tool or tool component surface and the amount of cooling surface area relative to molded tool, or component, surface area. Conventional machining and manufacturing methods are limited to how the cooling channels can be designed into the tool, because they are formed using a drill and must consider tool geometry. Therefore, the laminate tool process presents great opportunity to improve cooling efficiency because of the ability to create large surface area conformal cooling channels, and undulations in cooling channel surface to induce turbulent flow.
Aluminum brazing is typically performed on small surface areas required to be brazed and components that have a high volume/mass ratio. The most common type of aluminum brazing is performed in a nitrogen atmosphere using a flux braze process. Other brazing processes are fluxless vacuum brazing. Braze filler metals for flux atmosphere brazing includes foils and/or pastes.